When using the protected users global group, what is not a valid security restriction imposed on the group?

Question $26$ options:

Only higher$-$level encryption methods compatible with Kerberos security, such as Advanced Encryption Standard $($AES$)$ can be used.

Connections to systems that do not utilize this global group may not succeed.

Only computers running Windows $7$ or higher can be made member computers

Group members cannot use weaker forms of authentication, such as NTLM$,$ CredSSP, or digest authentication.